Carbonate Hardness (KH)

[GeoffBeck]

I am relatively new to tropical fish - 10gall tank set up 2 months ago - seems to have matured - nitrite levels virtually zero - wayer is very soft and also KH is very low (less than 3°d) and PH is 6.8 - all according to Tetra Test strip. Is there a way of increasing KH or is it not neccessary?

 

[Alien Anna]

A low KH is quite useful if you want soft water fish such as tetras (I have the opposite problem with my water). However, it does mean the pH is less well "cushioned". A couple of lumps of tufa rock would help increase it - it's a kind of limestone, I believe. You can get it in LFS's. Some sterilised coral skeletons would have a similar effect, or you can put a bag of coral sand in your filter. You don't want to over-do it, however - pH is not something newbies should really touch, and anything that effects KH can affect pH.